On Mon, Jun 06, 2016 at 04:29:04PM +0300, Mika Kahola wrote:
Read DisplayPort downstream port capabilities. Depending on the DP port the capabilities are defined in length of 1 byte or 4 bytes depending if the detailed capability information is available.
Signed-off-by: Mika Kahola mika.kahola@intel.com
drivers/gpu/drm/drm_dp_helper.c | 27 +++++++++++++++++++++++++++ include/drm/drm_dp_helper.h | 3 +++ 2 files changed, 30 insertions(+)
diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index eeaf5a7..c4149fd 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -438,6 +438,33 @@ int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link) } EXPORT_SYMBOL(drm_dp_link_configure);
+/**
- drm_dp_downstream_port_cap() - read downstream port capabilities
- @dpcd: DisplayPort configuration data
- @port_cap: port capabilities
- returns size of the port capabilites
- */
+int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],u8 port_cap[4])+{
- int size;
- bool detailed_cap_info = dpcd[DP_DOWNSTREAMPORT_PRESENT] &
DP_DETAILED_CAP_INFO_AVAILABLE;- if (detailed_cap_info) {
size = 4;drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, port_cap, size);- } else {
size = 1;drm_dp_dpcd_read(aux, DP_DOWNSTREAM_PORT_0, &port_cap[0], size);- }
Could avoid a bit of duplicatetion. Eg.: if (dpcd[DP_DOWNSTREAMPORT_PRESENT] & DP_DETAILED_CAP_INFO_AVAILABLE) size = 4; else size = 1;
return drm_dp_dpcd_read(...);
Though perhaps we should just read out the entire 4/16 bytes to get the caps for all the ports?
- return size;
+} +EXPORT_SYMBOL(drm_dp_downstream_port_cap);
/*
- I2C-over-AUX implementation
*/ diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index e384c7f..db8d3d47 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -806,6 +806,9 @@ int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link); int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link); int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link); int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link); +int drm_dp_downstream_port_cap(struct drm_dp_aux *aux,
const u8 dpcd[DP_RECEIVER_CAP_SIZE],u8 port_cap[4]);int drm_dp_aux_register(struct drm_dp_aux *aux); void drm_dp_aux_unregister(struct drm_dp_aux *aux); -- 1.9.1